L02_HashMDMAC

Team who broke md5 in summer 2004 found a the way to

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Unformatted text preview: nese Team who broke MD5 in summer 2004 found a The way to reduce the complexity of finding SHA-1 hash collisions from 8 280 to 2668 => i.e. a speed up of 4096 times SHA-1 Secure Hash Function append padding bits append length compression function: typically consists of shifting, bit-rotation, XOR, NOT, AND, OR. Much quicker to execute than encryption output Every bit of the hash code is a function of every bit of the input! RIPEMD-160 European RIPE Project – 1997 Same group launched an attack on MD5 Extended from 128 to 160-bit message digest Extended 160-bit Comparison of Secure HASH functions SHA-1 MD5 RIPEMD-160 Digest length 160 bits 128 bits 160 bits Basic unit of Basic processing processing 512 bits 512 bits 512 bits 80 (4 rounds of 80 20) 20) 64 (4 rounds of 64 16) 16) 160 (5 paired 160 rounds of 16) rounds Sample relative Speed (on 90MHz Pentium) http://www.esat.kuleuv en.ac.be/~bosselae/fas t.html 264-1 bits 6.88 Mbyte/sec 6.88 ∞ Maximum message Maximum size size 17.09 Mbyte/sec...
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